Decent bb cups are VERY hard and will ruin most hacksaw blades in a few strokes. You need a carbide blade, or better yet clamp the edge (assuming it has an accessable edge) of the fixed cup in a sturdy bench vise and use the frame as the lever to turn it out. If it has Raleigh or English threading be aware that the fixed cup is left-hand threaded and removes the opposite way from "normal".